To evaluate the safety/efficacy of in vivo gene transfer of the herpes simplex thymidine kinase gene using PA317/G1TkSvNa.7 vector producer cell in patients recurrent malignant glioma. Insertion of the HSV-Tk1 gene confers sensitivity to the anti-herpes drug ganciclovir. Direct injection of this VPC can result in destruction with ganciclovir therapy. We will focus on maximizing the relative number of vector producer cells to the tumor mass by stereotactically injecting VPD's into tumor mass.